Structuring liquid nonionic surfactants prior to granulation process

ABSTRACT

A process for making a granular laundry detergent component or composition having a bulk density of at least 650 g/l, comprises dissolving a structuring agent in a nonionic surfactant, said structuring agent comprising a polymer, to form a pumpable premix and finely dispersing said premix with an effective amount of powder at a given operating temperature wherein the premix has a viscosity of at least 350 mPas when measured at said operating temperature and at a shear rate of 25s- 1 . Preferred structurants comprise polymers having more than one functional hydroxyl group, especially polyvinyl alcohols, polyhydroxyacrylic acid polymers, and polymers such as polyvinyl pyrrolidone and PVNO, as well as sugars, artificial sweeteners and their derivatives. The premix is then processed into a granular detergent by any suitable process. Fine dispersion mixing, agglomeration, or spraying the premix onto a granular base product are preferred.

BACKGROUND OF THE INVENTION

The present invention relates to improving storage stability andphysical properties of granular detergents which are rich in nonionicsurfactant.

It is most useful with nonionic surfactants which are liquid at ambienttemperature, and are therefore mobile. Without a suitable structurant,the nonionic surfactant tends to leak from the powder and soak into thecardboard container which forms an unsightly stain. Although it ispossible to avoid this problem by using lower levels of nonionicsurfactant in the composition, or by selecting nonionic surfactantswhich have a higher solidification temperature, this limits theflexibility of formulation.

The use of nonionic surfactants in granular detergent applications hasbeen widely discussed in the prior art. The following referencesdescribe various processes and compositions for making granules whichcomprise nonionic surfactants.

U.S. Pat. No. 3,868,336, published 25th Feb., 1975 discloses the use ofa powder premix comprising perborate, tripolyphosphate, nonionicsurfactant and polyvinyl alcohol. The premix is dry added to otherdetergent components.

GB 2 137 221, published 3rd Oct., 1984 discloses a nonionic premix whichcomprises dissolved polyvinyl pyrrolidone (PVP) and soil releasepolymer. The premix is sprayed on to an absorbant detergent carrierparticle. The PVP is used as a stabiliser for the soil release polymer.

EPA 0 215 637, published on 25th Mar., 1987 discloses the use of sugarsand derivatives as structurants of spray dried detergent powders.Although nonionic surfactant may be present in such powders it isincorporated at relatively low levels (1.5% -4% in examples 1 to 5).Furthermore the spray dried powder has a low bulk density (324-574 g/l).

EPA 0 513 824, published 19th Nov., 1992, describes a process forgranulating nonionic detergent and the use of a surface coating agenthaving a particle size of less than 10 micrometers to give a powderhaving a high content of nonionic surfactant (10-60%) and a bulk densityof 0.6 to 1.2 g/ml. The use of polymers including polyethylene glycol,polyvinyl alcohol, polyvinyl pyrrolidone and carboxymethyl cellulose isdisclosed (page 13, lines 17-18). However, the benefits of using any ofthese polymers to structure or thicken the nonionic surfactant is notdisclosed.

WO 92 6160, published on 16th Apr., 1992. This application describes(example 14) a granular detergent composition prepared by finedispersion mixing in an Eirich RV02 mixer of a paste which comprisesN-methyl glucose amide and nonionic surfactant in the presence of sodiumcarbonate and zeolite. There is no suggestion to use polymers asstructuring agents.

One aspect of the present invention is a process for making granularnonionic detergent agglomerates having a bulk density of at least 650g/l and which comprise higher levels of nonionic surfactant than thoseof the prior art, but do not have problems of mobile nonionicsurfactants (i.e. nonionic surfactants with low solidificationtemperatures) leaking from the granules and soaking into the carton.

This problem is addressed by structuring the liquid nonionic surfactantbefore the dispersion and/or granulation process. This is done bydissolving a structuring agent which comprises a polymer in the nonionicsurfactant. Preferred structuring agents are polymers, especiallypolymers having more than one functional hydroxyl group, especiallypolyvinyl alcohols, polyhydroxyacrylic acid polymers, and polymers suchas polyvinyl pyrrolidone and PVNO. Also useful as components of thestructuring agent are sugars and artificial sweeteners and theirderivatives.

It is a further aspect of the present invention to provide a process forincorporating sticky materials into detergent granules while stillmaintaining desirable physical properties including free-flowingparticles which have a good resistance to caking. Sticky materials ifpresent at or close to the surface of the granules have a negativeeffect on flow properties. These materials also tend to gel upon contactwith water which prevents effective dispensing of the granules from thedispensing drawer of a washing machine or from a dispensing device whichis added to the wash with soiled load. In this aspect of the presentinvention these problems are overcome by using sticky materials asstructuring agents of the nonionic surfactants thereby improving thesurface properties of the granules.

In a further aspect of the invention, high bulk density granulardetergent compositions and components are provided which comprisenonionic surfactants and structuring agents.

SUMMARY OF THE INVENTION

A process for making a granular laundry detergent component orcomposition having a bulk density of at least 650 g/l, by dissolving astructuring agent in a nonionic surfactant, said structuring agentcomprising a polymer, to form a pumpable premix and finely dispersingsaid premix with an effective amount of powder at a given operatingtemperature wherein the premix has a viscosity of at least 350 mPas whenmeasured at said operating temperature and at a shear rate of 25s⁻¹.Preferred structurants comprise polymers having more than one functionalhydroxyl group, especially polyvinyl alcohols, polyhydroxyacrylic acidpolymers, and polymers such as polyvinyl pyrrolidone and PVNO, as wellas sugars, artificial sweeteners and their derivatives. The premix isthen processed into a granular detergent by any suitable process. Finedispersion mixing, agglomeration, or spraying the premix onto a granularbase product are preferred.

Another aspect of the present invention is components or compositionscomprising nonionic surfactant and structuring agents.

DETAILED DESCRIPTION OF THE INVENTION

The process aspect of the present invention comprises two essentialsteps. The first process step is the formation of a nonionic surfactantpremix which comprises a structuring agent. The second process step isthe processing of the surfactant premix into the form of a granulardetergent having the desired physical properties of bulk density, flowproperties and storage characteristics.

The first process step of the invention is the preparation of astructured nonionic surfactant premix. This premix comprises twoessential components which will be described in more detail below. Thesecomponents are the nonionic surfactant and the structuring agent. In thefirst process step the structuring agent is dissolved in the nonionicsurfactant.

The second process step may be based upon any of the techniques offorming granules which are known to the man skilled in the art. However,the most preferred granulation techniques for use in the presentinvention are fine dispersion of the structured nonionic surfactantpaste in the presence of powders. One example of such a process is topump or spray the surfactant paste into a high shear mixer. The highshear conditions in the mixer break up the surfactant paste into smalldroplets and distribute those droplets onto and around the powder. Theprocess is often described as "agglomeration".

Another example of such a process is to spray the surfactant paste ontoa powder under low shear conditions (such as a rotating drum). In thiscase the energy to break the paste into fine droplets comes at the spraynozzle, and in the low shear mixer the droplets are absorbed on to thesurface, or into the pores of the powder. Preferred granulationprocesses are described in more detail below.

For the purposes of the invention described herein, the term structuringhas been used to mean thickening or raising the solidification point ofthe nonionic surfactant, or both of these. It is an essential feature ofthe present invention that the viscosity of the premix is greater than350 mPas when measured at the operating temperature and at a shear rateof 25s⁻¹.

The operating temperature, as defined herein, is the temperature of thesurfactant paste at the point which is sprayed or dispersed onto thepowders during the granulation step of the process.

A pumpable paste is defined herein to mean a paste which has a viscosityof less than 100 000 mPas when measured at 25s⁻¹ at the requiredoperating temperature. Preferably the viscosity of the paste will beless than 60 000 mPas, and even more preferably less than 40 000 mPas.

Nonionic Surfactant

Suitable nonionic surfactants include compounds produced by thecondensation of alkylene oxide groups (hydrophilic in nature) with anorganic hydrophobic compound, which may be aliphatic or alkyl aromaticin nature. The length of the polyoxyalkylene group which is condensedwith any particular hydrophobic group can be readily adjusted to yield awater-soluble compound having the desired degree of balance betweenhydrophilic and hydrophobic elements.

Particularly preferred for use in the present invention are nonionicsurfactants such as the polyethylene oxide condensates of alkyl phenols,e.g., the condensation products of alkyl phenols having an alkyl groupcontaining from about 6 to 16 carbon atoms, in either a straight chainor branched chain configuration, with from about 4 to 25 moles ofethylene oxide per mole of alkyl phenol.

Preferred nonionics are the water-soluble condensation products ofaliphatic alcohols containing from 8 to 20 carbon atoms, in eitherstraight chain or branched configuration, with an average of from 1 to25 moles of ethylene oxide per mole of alcohol. Particularly preferredare the condensation products of alcohols having an alkyl groupcontaining from about 9 to 15 carbon atoms with from about 2 to 10 molesof ethylene oxide per mole of alcohol; and condensation products ofpropylene glycol with ethylene oxide. Most preferred are condensationproducts of alcohols having an alkyl group containing from about 12 to15 carbon atoms with an average of about 3 moles of ethylene oxide permole of alcohol.

Many of the nonionic surfactants which fall within the definitions givenabove are liquid at temperatures below 40° C. (that is to say thesolidification temperature is below 40° C.). The present invention hasbeen found to be particularly useful for such nonionic surfactants.

Structuring Agent

Although any structuring agent may be chosen which has the effect ofraising the viscosity or "stickiness" of the surfactant premix to therequired operating window and/or increasing the solidificationtemperature of the premix, it has been found that structuring agentswhich comprise at least one polymer are particularly useful.

Preferably at least one of the components of the structuring agent is apolymer having an average molecular weight of at least 2000, andpreferably at least 10000.

The group of polymers useful as structuring agents in the presentinvention includes the group of polymers which are derived from monomershaving at least one hydroxyl functional group such as polyvinylalcohols, polyethylene glycol and polyhydroxyacrylic acid polymers andmixtures and derivatives of these. Other polymers which are usefulcomponents of the strucuring agent include polyvinyl pyrollidone, PVNO.

The structuring agent may also comprise other ingredients. One group ofsuch ingredients which have been found to be particularly usefulcomprises the group of sugars and artificial sweeteners and theirderivatives.

The group of sugars useful in the present invention includes fructose,lactose, dextrose, sucrose, saccharin and sorbitol.

One particularly preferred group of structuring agents is thederivatives of sugars such as polyhydroxy fatty acid amides. Suchderivatives may be prepared by reacting a fatty acid ester and anN-alkyl polyhydroxy amine. The preferred amine for use in the presentinvention is N-(R1).CH--CH2(CH2OH)4--CH2--OH and the preferred ester isa C12-C20 fatty acid methyl ester. Most preferred is the reactionproduct of N-methyl glucamine (which may be derived from glucose) withC12-C20 fatty acid methyl ester.

Methods of manufacturing polyhydroxy fatty acid amides have beendescribed in WO 92 6073, published on 16th Apr., 1992. This applicationdescribes the preparation of polyhydroxy fatty acid amides in thepresence of solvents.

In a highly preferred embodiment of the invention N-methyl glucamine isreacted with a C12-C20 methyl ester. It also says that the formulator ofgranular detergent compositions may find it convenient to run theamidation reaction in the presence of solvents which comprisealkoxylated, especially ethoxylated (EO 3-8) C12-C14 alcohols (page 15,lines 22-27). This directly yields nonionic surfactant systems which arepreferred in the present invention, such as those comprising N-methylglucamide and C12-C14 alcohols with an average Of 3 ethoxylate groupsper molecule.

Polyhydroxy fatty acid amides are also active in the washing process assurfactants in their own right.

Other ingredients which have been found to be useful as components ofthe structuring agent include phthalimide, para-toluene sulphonamide,and maleimide.

The ratio of nonionic surfactant to structuring agent will varyaccording to exactly which nonionic surfactant and which structurant ischosen. Any ratio may be used in the present invention provided that apremix having a viscosity of at least 350 mPas when measured at theoperating temperature and a shear rate of 25s⁻¹ is produced. Typicallyratios of nonionic surfactant to structuring agent in the range of 20:1to 1:1 have been found to be particularly suitable, and preferably from5:1 to 2:1.

Normally the detergent compositions made according to the presentinvention may include a wide range of other ingredients and componentswhich are known to the man skilled in the art to have a function in thewashing process. Typical examples of such ingredients which may be usedin detergent compositions are given below.

Granulation Processes

An essential step of the present invention is the process of forminggranules which comprise the surfactant premix described above. Manyprocesses for granulating surfactant pastes are known to the man skilledin the art. One of these processes is spray drying of a slurrycontaining the surfactant. However, this is not a preferred process inthe present invention because it does not generally yield a powder witha high bulk density, and further processing is needed in order toincrease the bulk density. A process which is more suited to the presentinvention is that of fine dispersion mixing or agglomeration. In thisprocess a powder having a relatively small particle size is mixed with afinely dispersed paste which causes the powder to stick together (oragglomerate). The result is a granular composition which generally has aparticle size distribution in the range of 250 to 1200 micrometers andhas a bulk density of at least 650 g/l. In the present invention thesurfactant premix is used as the paste which is finely dispersed with aneffective amount of powder in a suitable mixer. Suitable mixers forcarrying out the fine dispersion mixing are described in more detailbelow. Any suitable powder may be chosen by mixing one or more of theingredients listed below which may be conveniently handled in powderform. Powders comprising zeolite, carbonate, silica, silicate,sulphate,phosphate, citrate, citric acid and mixtures of these are particularlypreferred.

It has further been found that a particularly preferred embodiment ofthe present invention is to spray water on to the detergent granulesafter the granulation step. In this embodiment of the invention at leastone of the powders used should be an anhydrous powder which may be fullyor partially hydrated when it comes into contact with water. A similarprocess has been described in GB 2 113 707, published on 10th Aug. 1983.This application describes a process in which anhydrous powders such asphosphate, carbonate, borate or sulphate are metered into a high shearmixer (a K-G Schugi [Trade name] Blender-Agglomerator) together with aliquid surfactant and water. The amount of water added is sufficient tocompletely hydrate the hydratable salts. The resulting agglomerates arefed into a low shear mixer having a longer residence time in order forthe hydration reaction to proceed.

In the process of the present invention, in contrast, it is highlypreferred to add the water into the low shear mixer, after theagglomerates have been formed. Without wishing to be bound by theory, itis believed that adding the water after the initial formation of theagglomerates promotes hydration at the surface of the agglomerates whichgives rise to the desired physical characteristics.

Most preferred in the process of the present invention is the use ofanhydrous sodium carbonate, or anhydrous sodium citrate, or mixtures ofthese. The anhydrous salts are agglomerated in the presence of astructured nonionic surfactant premix and then water is sprayed on tothe resulting agglomerates in a low shear mixer. The agglomerates arefinally dried in a fluid bed dryer.

Still another process which is suited to the present invention is thatof preparing a granular detergent powder and spraying the surfactantpremix onto that powder. The base powder may be made by any one of theprocesses known to the man skilled in the art, including spray drying,granulation,. (including agglomeration). Preferably different processeswhich are suited to the preparation of different components will beused, and then the components will be mixed together, for example by drymixing in a rotating drum or a low shear mixer. In a preferredembodiment of the invention the surfactant premix is sprayed onto thebase powder in the rotating drum or low shear mixer. p Suitable piecesof equipment in which to carry out the fine dispersion mixing orgranulation of the present invention are mixers of the Fukae® FS-Gseries manufactured by Fukae Powtech Kogyo Co., Japan; this apparatus isessentially in the form of a bowl-shaped vessel accessible via a topport, provided near its base with a stirrer having a substantiallyvertical axis, and a cutter positioned on a side wall. The stirrer andcutter may be operated independently of one another and at separatelyvariable speeds. The vessel can be fitted with a cooling jacket or, ifnecessary, a cryogenic unit.

Other similar mixers found to be suitable for use in the process of theinvention include Diosna® V series ex Dierks & Sohne, Germany; and thePharma Matrix® ex T K Fielder Ltd., England. Other mixers believed to besuitable for use in the process of the invention are the Fuji® VG-Cseries ex Fuji Sangyo Co., Japan; and the Roto® ex Zanchetta & Co srl,Italy.

Other preferred suitable equipment can include Eirich®, series RV,manufactured by Gustau Eirich Hardheim, Germany; Lodige®, series FM forbatch mixing, series Baud KM for continuous mixing/agglomeration,manufactured by Lodige Machinenbau GmbH, Paderborn Germany; Drais® T160series, manufactured by Drais Werke GmbH, Mannheim Germany; andWinkworth® RT 25 series, manufactured by Winkworth Machinery Ltd.,Berkshire, England.

The Littleford Mixer, Model #FM-130-D-12, with internal chopping bladesand the Cuisinart Food Processor, Model #DCX-Plus, with 7.75 inch (19.7cm) blades are two examples of suitable mixers. Any other mixer withfine dispersion mixing and granulation capability and having a residencetime in the order of 0.1 to 10 minutes can be used. The "turbine-type"impeller mixer, having several blades on an axis of rotation, ispreferred. The invention can be practiced as a batch or a continuousprocess.

Further Processing Steps

The granular components or compositions described above may be suitablefor use directly, or they may be treated by additional process steps.Commonly used process steps include drying, cooling and/or dusting thegranules with a finely divided flow aid. In addition the granules may beblended with other components in order to provide a composition suitablefor the desired end use. Any type of mixer or dryer (such as fluid beddryers) may be found to be suitable for this purpose. The finely dividedflow aid, if used, may be chosen from a wide variety of suitableingredients such as zeolite, silica, talc, clay or mixtures of these.

Compositions

Another aspect of the present invention is the composition of detergentcomponents comprising nonionic surfactant. Components having a bulkdensity of greater than 650 g/l and comprising from 10% to 50% by weightof nonionic surfactant and from 5% to 30% by weight of one of thestructuring agents listed above fall within the scope of the presentinvention. The ratio of nonionic surfactant to structuring-agent willvary according to exactly which nonionic surfactant and whichstructurant is chosen. Any ratio may be used in the present inventionprovided that a premix having a viscosity of at least 350 mPas whenmeasured at the operating temperature and a shear rate of 25s⁻¹ isproduced. Typically ratios of nonionic surfactant to structuring agentin the range of 20:1 to 1:1 have been found to be particularly suitable,and preferably from 5:1 to 2:1.

Other ingredients which may be used in making the compositions of thepresent invention will be described below.

Normally the granular detergent will also contain other optionalingredients. Examples of such ingredients which are commonly used indetergents are given in more detail hereinbelow

Anionic Surfactants

Alkyl Ester Sulfonate Surfactant

Alkyl Ester sulfonate surfactants hereof include linear esters of C₈-C₂₀ carboxylic acids (i.e. fatty acids) which are sulfonated withgaseous SO₃ according to "The Journal of the American Oil ChemistsSociety'" 52 (1975), pp. 323-329. Suitable starting materials wouldinclude natural fatty substances as derived from tallow, palm oil, etc.

The preferred alkyl ester sulfonate surfactant, especially for laundryapplications, comprises alkyl ester sulfonate surfactants of thestructural formula: ##STR1## wherein R³ is a C₈ -C₂₀ hydrocarbyl,preferably an alkyl, or combination thereof, R⁴ is a C₁ -C₆ hydrocarbyl,preferably an alkyl, or combination thereof, and M is a cation whichforms a water soluble salt with the alkyl ester sulfonate. Suitablesalt-forming cations include metals such as sodium, potassium, andlithium, and substituted or unsubstituted ammonium cations, such asmonoethanolamine, diethanolamine, and triethanolamine. Preferably, R³ isC₁₀ -C₁₆ alkyl, and R⁴ is methyl, ethyl or isopropyl. Especiallypreferred are the methyl ester sulfonates wherein R³ is C₁₄ -C₁₆ alkyl.

Alkyl Sulfate Surfactant

Alkyl sulfate surfactants hereof are water soluble salts or acids or theformula ROSO₃ M wherein R preferably is a C₁₀ -C₂₄ hydrocarbyl,preferably an alkyl or hydroxyalkyl having a C₁₀ -C₂₀ alkyl component,more preferably a C₁₂ -C₁₈ alkyl or hydroxyalkyl, and M is H or acation, e.g., an alkali metal cation (e.g., sodium, potassium, lithium),or ammonium or substituted ammonium (e.g., methyl-, dimethyl-, andtrimethyl ammonium cations and quaternary ammonium cations, such astetramethyl-ammonium and dimethyl piperdinium cations and quarternaryammonium cations derived from alkylamines such as ethylamine,diethylamine, triethylamine, and mixtures thereof, and the like).Typically, alkyl chains of C₁₂₋₁₆ are preferred for lower washtemperatures (e.g., below about 50° C.) and C₁₆₋₁₈ alkyl chains arepreferred for higher wash temperatures (e.g., above about50° C.).

Alkyl Alkoxylated Sulfate Surfactant

Alkyl alkoxylated sulfate surfactants hereof are water soluble salts oracids of the formula RO(A)_(m) SO₃ M wherein R is an unsubstituted C₁₀-C₂₄ alkyl or hydroxyalkyl group having a C₁₀ -C₂₄ alkyl component,preferably a C₁₂ -C₂₀ alkyl or hydroxyalkyl, more preferably C₁₂ -C₁₈alkyl or hydroxyalkyl, A is an ethoxy or propoxy unit, m is greater thanzero, typically between about 0.5 and about 6, more preferably betweenabout 0.5 and about 3, and M is H or a cation which can be, for example,a metal cation (e.g., sodium, potassium, lithium, calcium, magnesium,etc.), ammonium or substituted-ammonium cation. Alkyl ethoxylatedsulfates as well as alkyl propoxylated sulfates are contemplated herein.Specific examples of substituted ammonium cations include methyl-,dimethyl-, trimethylammonium and quaternary ammonium cations, such astetramethyl-ammonium, dimethyl piperdinium and cations derived fromalkanolamines such as ethylamine, diethylamine, triethylamine, mixturesthereof, and the like. Exemplary surfactants are C₁₂ -C₁₈ alkylpolyethoxylate (1.0) sulfate, C₁₂ -C₁₈ E(1.0)M), C₁₂ -C₁₈ alkylpolyethoxylate (2.25) sulfate, C₁₂ -C₁₈ E(2.25)M), C₁₂ -C₁₈ alkylpolyethoxylate (3.0) sulfate C₁₂ -C₁₈ E(3.0), and C₁₂ -C₁₈ alkylpolyethoxylate (4.0) sulfate C₁₂ -C₁₈ E(4.0)M), wherein M isconveniently selected from sodium and potassium.

Other Anionic Surfactants

Other anionic surfactants useful for detersive purposes can also beincluded in the laundry detergent compositions of the present invention.These can include salts (including, for example, sodium, potassium,ammonium, and substituted ammonium salts such as mono-, di- andtriethanolamine salts) of soap, C₉ -C₂₀ linear alkylbenzenesulphonates,C₈ -C₂₂ primary or secondary alkanesulphonates, C₈ -C₂₄olefinsulphonates, sulphonated polycarboxylic acids prepared bysulphonation of the pyrolyzed product of alkaline earth metal citrates,e.g., as described in British patent specification No. 1,082,179, C₈-C₂₄ alkylpolyglycolethersulfates (containing up to 10 moles of ethyleneoxide); acyl glycerol sulfonates, fatty oleyl glycerol sulfates, alkylphenol ethylene oxide ether sulfates, paraffin sulfonates, alkylphosphates, isethionates such as the acyl isethionates, N-acyl taurates,alkyl succinamates and sulfosuccinates, monoesters of sulfosuccinate(especially saturated and unsaturated C₁₂ -C₁₈ monoesters) diesters ofsulfosuccinate (especially saturated and unsaturated C₆ -C₁₄ diesters),acyl sarcosinates, sulfates of alkylpolysaccharides such as the sulfatesof alkylpolyglucoside, branched primary alkyl sulfates, alkyl polyethoxycarboxylates such as those of the formula RO(CH₂ CH₂₀)_(k) CH₂ COO--M⁺wherein R is a C₈ -C₂₂ alkyl, k is an integer from 0 to 10, and M is asoluble salt-forming cation. Resin acids and hydrogenated resin acidsare also suitable, such as rosin, hydrogenated rosin, and resin acidsand hydrogenated resin acids present in or derived from tall oil.Further examples are given in "Surface Active Agents and Detergents"(Vol. I and II by Schwartz, Perry and Berch). A variety of suchsurfactants are also generally disclosed in U.S. Pat. No. 3,929,678,issued Dec. 30, 1975 to Laughlin, et al. at Column 23, line 58 throughColumn 29, line 23 (herein incorporated by reference).

When included therein, the laundry detergent compositions of the presentinvention typically comprise from about 1% to about 40%, preferably fromabout 3% to about 20% by weight of such anionic surfactants.

Other Surfactants

The laundry detergent compositions of the present invention may alsocontain cationic, ampholytic, zwitterionic, and semi-polar surfactants,as well as nonionic surfactants other than those already describedherein, including the semi-polar nonionic amine oxides described below.

Cationic detersive surfactants suitable for use in the laundry detergentcompositions of the present invention are those having one long-chainhydrocarbyl group. Examples of such cationic surfactants include theammonium surfactants such as alkyldimethylammonium halogenides, andthose surfactants having the formula:

    R.sup.1 R.sup.2 R.sup.3 R.sup.4 N.sup.+ X.sup.-

wherein R¹ is an alkyl or alkyl benzyl group having from about 8 toabout 18 carbon atoms in the alkyl chain, each of R², R³, R⁴ isindependently C₁ -C₄ alkyl, C₁ -C₄ hydroxy alkyl, benzyl, and --(C₂H₄)xH where x has a value from 2 to 5, and X⁻ is an anion. Not more thanone of R₂, R₃, R₄ should be benzyl.

The preferred alkyl chain length for R¹ is C₁₂ -C₁₅, particularly wherethe alkyl group is a mixture of chain lengths derived from coconut orpalm kernel fat, or is derived synthetically by olefin build up or OXOalcohols synthesis. Preferred groups for R₂, R₃, R₄ are methyl andhydroxyethyl groups, and the anion X may be selected from halide,methosulphate, acetate and phosphate ions. Examples of suitablequaternary ammonium compounds for use herein are:

coconut trimethyl ammonium chloride or bromide

coconut methyl dihydroxyethyl ammonium chloride or bromide

decyl triethyl ammonium chloride or bromide

decyl dimethyl hydroxyethyl ammonium chloride or bromide

C12-14 dimethyl hydroxyethyl ammonium chloride or bromide

myristyl trimethyl ammonium methyl sulphate

lauryl dimethyl benzyl ammonium chloride or bromide lauryl methyl(ethenoxy)₄ ammonium chloride or bromide

The above water-soluble cationic components of the compositions of thepresent invention, are capable of existing in cationic form in a 0.1%aqueous solution at pH10.

Other cationic surfactants useful herein are also described in U.S. Pat.No. 4,228,044, Cambre, issued Oct. 14, 1980, incorporated herein byreference. p When included therein, the laundry detergent compositionsof the present invention typically comprise from 0% to about 25%,preferably form about 3% to about 15% by weight of such cationicsurfactants.

Ampholytic surfactants are also suitable for use in the laundrydetergent compositions of the present invention. These surfactants canbe broadly described as aliphatic derivatives of secondary or tertiaryamines, or aliphatic derivatives of heterocyclic secondary and tertiaryamines in which the aliphatic radical can be straight- or branchedchain. One of the aliphatic substituents contains at least 8 carbonatoms, typically from about 8 to about 18 carbon atoms, and at least onecontains an anionic water-solubilizing group e.g. carboxy, sulfonate,sulfate. See U.S. Pat. No. 3,929,678 to Laughlin et al., issued Dec. 30,1975 at column 19, lines 18-35 (herein incorporated by reference) forexamples of ampholytic surfactants.

When included therein, the laundry detergent compositions of the presentinvention typically comprise form 0% to about 15%, preferably from about1% to about 10% by weight of such ampholytic surfactants.

Zwitterionic surfactants are also suitable for use in laundry detergentcompositions. These surfactants can be broadly described as derivativesof secondary and tertiary amines, derivates of heterocyclic secondaryand tertiary amines, or derivatives of quaternary ammonium, quarternaryphosphonium or tertiary sulfonium compounds. See U.S. Pat. No. 3,929,678to Laughlin et al., issued Dec. 30, 1975 at columns 19, line 38 throughcolumn 22, line 48 (herein incorporated by reference) for examples ofzwitterionic surfactants.

When included therein, the laundry detergent compositions of the presentinvention typically comprise form 0% to about 15%, preferably from about1% to about 10% by weight of such zwitterionic surfactants.

Semi-polar nonionic surfactants are a special category of nonionicsurfactants which include water-soluble amine oxides containing onealkyl moiety of from about 10 to about 18 carbon atoms and 2 moietiesselected from the group consisting af alkyl groups and hydrocyalkylgroups containing form about 1 to about 3 carbon atoms; water-solublephosphine oxides containing one alkyl moiety of form about 10 to about18 carbon atoms and 2 moieties selected form the group consisting ofalkyl groups and hydroxyalkyl groups containing from about 1 to about 3carbon atoms.

Semi-polar nonionic detergent surfactants include the amine oxidesurfactants having the formula: ##STR2## wherein R³ is an alkyl,hydroxyalkyl, or alkyl phenyl group or mixtures thereof containing fromabout 8 to about 22 carbon atoms; R⁴ is an alkylene or hydroxyalkylenegroup containing from about 2 to about 3 carbon atoms or mixturesthereof; x is form 0 to about 3; and each R⁵ is an alkyl or hydroxyalkylgroup containing form about 1 to about 3 carbon atoms or a polyethyleneoxide group containing from about 1 to about 3 ethylene oxide groups.The R⁵ groups can be attached to each other, e.g., through an oxygen ornitrogen atom, to form a ring structure.

There amine oxide surfactants in particular include C₁₀ -C₁₈ alkyldimenthyl amine oxides and C₈ -C₁₂ alkoxy ethyl dihydroxy ethyl amineoxides. p When included therein, the laundry detergent compositions ofthe present invention typically comprise form 0% to about 15%,preferably from about 1% to about 10% by weight of such semi-polarnonionic surfactants.

Builders and Other Optional Ingredients

Sodium aluminosilicate may take many forms. One example is crystallinealuminosilicate ion exchange material of the formula

    Na.sub.z [(AlO.sub.2).sub.z. (SiO.sub.2).sub.y ]. xH.sub.2 O

wherein z and y are at least about 6, the molar ratio of z to y is fromabout 1.0 to about 0.4 and z is from about 10 to about 264. Amorphoushydrated aluminosilicate materials useful herein have the empiricalformula

    M.sub.z (zAlO.sub.2. ySiO.sub.2)

wherein M is sodium, potassium, ammonium or substituted ammonium, z isfrom about 0.5 to about 2 and y is 1, said material having a magnesiumion exchange capacity of at least about 50 milligram equivalents ofCaCO₃ hardness per gram of anhydrous aluminosilicate. Hydrated sodiumZeolite A with a particle size of from about 1 to 10 microns ispreferred.

The aluminosilicate ion exchange builder materials herein are inhydrated form and contain from about 10% to about 28% of water by weightif crystalline, and potentially even higher amounts of water ifamorphous. Highly preferred crystalline aluminosilicate ion exchangematerials contain from about 18% to about 22% water in their crystalmatrix. The crystalline aluminosilicate ion exchange materials arefurther characterized by a particle size diameter of from about 0.1micron to about 10 microns. Amorphous materials are often smaller, e.g.,down to less than about 0.01 micron. Preferred ion exchange materialshave a particle size diameter of from about 0.2 micron to about 4microns. The term "particle size diameter" herein represents the averageparticle size diameter by weight of a given ion exchange material asdetermined by conventional analytical techniques such as, for example,microscopic determination utilizing a scanning electron microscope. Thecrystalline aluminosilicate ion exchange materials herein are usuallyfurther characterized by their calcium ion exchange capacity, which isat least about 200 mg equivalent of CaCO₃ water hardness/g ofaluminosilicate, calculated on an anhydrous basis, and which generallyis in the range of from about 300 mg eq./g to about 352 mg eq./g. Thealuminosilicate ion exchange materials herein are still furthercharacterized by their calcium ion exchange rate which is at least about2 grains Ca⁺⁺ /gallon/minute/gram/gallon of aluminosilicate (anhydrousbasis), and generally lies within the range of from about 2grains/gallon/minute/gram/gallon to about 6grains/gallon/minute/gram/gallon, based on calcium ion hardness. Optimumaluminosilicate for builder purposes exhibit a calcium ion exchange rateof at least about 4 grains/gallon/minute/gram/gallon.

The amorphous aluminosilicate ion exchange materials usually have a Mg⁺⁺exchange of at least about 50 mg eq. CaCO₃ /g (12 mg Mg⁺⁺ /g) and a Mg⁺⁺exchange rate of at least about 1 grain/gallon/minute/gram/gallon.Amorphous materials do not exhibit an observable diffraction patternwhen examined by Cu radiation (1.54 Angstrom Units).

Aluminosilicate ion exchange materials useful in the practice of thisinvention are commercially available. The aluminosilicates useful inthis invention can be crystalline or amorphous in structure and can benaturally occurring aluminosilicates or synthetically derived. A methodfor producing aluminosilicate ion exchange materials is discussed inU.S. Pat. No. 3,985,669, Krummel et al., issued Oct. 12, 1976,incorporated herein by reference. Preferred synthetic crystallinealuminosilicate ion exchange materials useful herein are available underthe designations Zeolite A, Zeolite B, Zeolite M and Zeolite X. In anespecially preferred embodiment, the crystalline aluminosilicate ionexchange material has the formula

    Na.sub.12 [(AlO.sub.2).sub.12 (SiO.sub.2).sub.12 ]. xH.sub.2 O

wherein x is from about 20 to about 30, especially about 27 and has aparticle size generally less than about 5 microns.

Other ingredients which are known for use in the components andcompositions may also be used as optional ingredients in the presentinvention.

The granular detergents of the present invention can contain neutral oralkaline salts which have a pH in solution of seven or greater, and canbe either organic or inorganic in nature. The builder salt assists inproviding the desired density and bulk to the detergent granules herein.While some of the salts are inert, many of them also function asdetergency builder materials in the laundering solution.

Examples of neutral water-soluble salts include the alkali metal,ammonium or substituted ammonium chlorides, fluorides and sulfates. Thealkali metal, and especially sodium, salts of the above are preferred.Sodium sulfate is typically used in detergent granules and is aparticularly preferred salt. Citric acid and, in general, any otherorganic or inorganic acid may be incorporated into the granulardetergents of the present invention as long as it is chemicallycompatible with the rest of the agglomerate composition.

Other useful water-soluble salts include the compounds commonly known asdetergent builder materials. Builders are generally selected from thevarious water-soluble, alkali metal, ammonium or substituted ammoniumphosphates, polyphosphates, phosphonates, polyphosphonates, carbonates,silicates, borates, and polyhyroxysulfonates. Preferred are the alkalimetal, especially sodium, salts of the above.

Specific examples of inorganic phosphate builders are sodium andpotassium tripolyphosphate, pyrophosphate, polymeric metaphosphatehaving a degree of polymerization of from about 6 to 21, andorthophosphate. Examples of polyphosphonate builders are the sodium andpotassium salts of ethylene diphosphonic acid, the sodium and potassiumsalts of ethane 1-hydroxy-1,1-diphosphonic acid and the sodium andpotassium salts of ethane, 1,1,2-triphosphonic acid. Other phosphorusbuilder compounds are disclosed in U.S. Pat. Nos. 3,159,581; 3,213,030;3,422,021; 3,422,137; 3,400,176 and 3,400,148, incorporated herein byreference.

Examples of nonphosphorus, inorganic builders are sodium and potassiumcarbonate, bicarbonate, sesquicarbonate, tetraborate decahydrate, andsilicate having a moiar ratio of SiO₂ to alkali metal oxide of fromabout 0.5 to about 4.0, preferably from about 1.0 to about 2.4.

As mentioned above powders normally used in detergents such as zeolite,carbonate, silica, silicate, citrate, phosphate, perborate, etc. andprocess acids such as starch, can be used in preferred embodiments ofthe present invention.

Polymers

Also useful are various organic polymers, some of which also mayfunction as builders to improve detergency. Included among such polymersmay be mentioned sodium carboxy-lower alkyl celluloses, sodium loweralkyl celluloses and sodium hydroxy-lower alkyl celluloses, such assodium carboxymethyl cellulose, sodium methyl cellulose and sodiumhydroxypropyl cellulose, polyvinyl alcohols (which often also includesome polyvinyl acetate), polyacrylamides, polyacrylates and variouscopolymers, such as those of maleic and acrylic acids. Molecular weightsfor such polymers vary widely but most are within the range of 2,000 to100,000.

Polymeric polycarboxylate builders are set forth in U.S. Pat. No.3,308,067, Diehl, issued Mar. 7, 1967. Such materials include thewater-soluble salts of homo-and copolymers of aliphatic carboxylic acidssuch as maleic acid, itaconic acid, mesaconic acid, fumaric acid,aconitic acid, citraconic acid and methylenemalonic acid.

Other Optionals Ingredients

Other ingredients commonly used in detergent compositions can beincluded in the components and compositions of the present invention.These include color speckles, bleaching agents and bleach activators,suds boosters or suds suppressors, antitarnish and anticorrosion agents,soil suspending agents, soil release agents, dyes, fillers, opticalbrighteners, germicides, pH adjusting agents, nonbuilder alkalinitysources, hydrotropes, enzymes, enzyme-stabilizing agents, and perfumes.

EXAMPLES

In these examples the following abbreviations have been used:

C25E3: C12-15 alkyl ethoxylate, with an average of 3 ethoxy groups permolecule

GA: N-methyl glucamide

C25AS: C12-15 alkyl sulphate

C45AS: C14-15 alkyl sulphate

C25AE3S: C12-15 alkyl ethoxy sulphate, with an average of 3 ethoxygroups per molecule

PVP: Polyvinyl Pyrrolidone

PVNO: Polyvinyl Pyrridine N oxide

                                      TABLE 1                                     __________________________________________________________________________    Ex    1  2  3  4  5   6   7   8   9   10 A                                    __________________________________________________________________________    C25E3 80 75 67 67 46  46  46  75  67  86 97.5                                 GA                            12.5                                                                              11                                          PVP   20 25 33 33                 22  14 2.5                                  PVNO              13  13  13  12.5                                            lactose           11                                                          dextrose              11                                                      sucrose                   11                                                  water             30  30  30                                                  Operating                                                                           30 30 15 15 20  20  20  40  40  20 20                                   Temp.(°C.)                                                             Viscosity                                                                           900                                                                              1300                                                                             2000                                                                             2000                                                                             23000                                                                             23000                                                                             23000                                                                             24000                                                                             15000                                                                             380                                                                              50                                   (mPas)                                                                        __________________________________________________________________________

Example 1

The C25E3/PVP paste defined in Table 1 was sprayed into a Loedige CBmixer [Trade Name] at a rate of 1120 kg/hr and at a temperature of 30°C. At the same time zeolite A was added to the mixer at a rate of 1340kg/hr, as well as anhydrous carbonate 1340 kg/hr.

Dispersion of the paste premix and high intensity mixing of the premixand the powders occurred in the Loedige mixer. The residence time wasapproximately eight seconds. The resulting mixture was fed into aLoedige KM mixer [Trade Name] and distinct agglomerates were formed. Twohigh speed choppers in the first half of the Loedige KM mixer preventeda high proportion of oversize agglomerates being formed.

In the second half of the Loedige KM mixer water was sprayed on to theagglomerates at a rate of 225 kg/hr promoting the hydration of thecarbonate in the agglomerate.

After the water spray on, a mixture of zeolite and silica was added at arate of 160 kg/hr. The agglomerates leaving the Loedige KM mixer werethen passed through a fluid bed cooler/elutriator

The resulting agglomerates had excellent physical properties includingflowability, and were found to be physically stable under stressedstorage conditions.

Example 2

The process of example 1 was repeated using the components listed inTable 1.

Example 3

The process of example 1 was repeated using the components listed inTable 1 and at an operating temperature of the paste premix of 15° C.

Example 4

The process of example 3 was repeated using the components listed inTable 1, with the Zeolite A being replaced by anhydrous citrate, and therate of water addition being increased to 190 kg/hr.

Example 5

The C25E3/PVNO/lactose paste defined in Table 1 was sprayed into aLoedige CB mixer [Trade Name] at a rate of 1400 kg/hr and at atemperature of 20° C. At the same time zeolite A was added to the mixerat a rate of 1200 kg/hr, as well as anhydrous carbonate 1200 kg/hr. Theremainder of the process was carried out as in example 1 with waterbeing sprayed on to the agglomerates at a rate of 200 kg/hr.

Examples 6-10

The process of example 5 was repeated using the components listed inTable 1.

In each of the examples 2 to 10, a free flowing granular products wereproduced which were found to be physically stable under stressed storageconditions.

Comparative Example A

The process of example 5 was repeated using the components listed inTable 1. Due to the lower viscosity of the surfactant premix it was notpossible to make granules having the desired particle size or physicalproperties.

We claim:
 1. A process for making a granular laundry detergent componentor composition having a bulk density of at least 650 g/l comprising thesteps of:a) dissolving a structuring agent, said structuring agentcomprising a polymer, in a nonionic surfactant to form a pumpablepremix; and b) finely dispersing said premix wiih an effective amount ofpowder characterized in that the fine dispersing of the premix is cardedout at an operating temperature of from about 15° to 30° C., and atwhich the premix has a viscosity of from about 380 to about 23,000 mPaswhen measured at said operating temperature and at a shear rate of 25s⁻¹; wherein said powder is selected from the group consisting of zeolite,silica, carbonate, silicate, sulfate, phosphate, citrate, citric acid ormixtures of these.
 2. A process according to claim 1 wherein thestructuring agent comprises at least one ingredient having more than onehydroxyl functional group.
 3. A process according to claim 2 wherein thestructuring agent is selected from the group consisting of dextrose,lactose, sucrose, saccharin and derivatives, including polyhydroxy fattyacid amides.
 4. A process according to claim 1 wherein the structuringagent is selected from the group consisting of polyvinyl pyrrolidone,polyvinyl pyrridinc N oxide, polyvinyl alcohols, polyhydroxyacrylic acidpolymers, and mixtures of these.
 5. A process according claim 4characterized in that the structuring agent is a polymer having amolecular weight of at least
 2000. 6. A process according to claim 1wherein the structuring agent is selected from the group consisting ofphthalimide, para-toluene sulphonamide, maleimide and mixtures of these.7. A process according claim 1 wherein the granular laundry detergentcomponent or composition comprises at least 10% by weight of nonionicsurfactant.
 8. A process for making a granular laundry detergentcomponent or composition having a bulk density of at least 650 g/lcomprising the steps of:a) dissolving a structuring agent, saidstructuring agent comprising a polymer, in a nonionic surfactant to forma premix; and b) mixing said premix with an effective amount of powderby spraying said premix onto said powder in a low shear mixer or arotating drum characterized in that the premix is sprayed at anoperating temperature of from about 15° to about 30° C., and at whichsaid premix has a viscosity of from about 380 to about 23,000 mPas whenmeasured at said operating temperature and at a shear rate of 25s⁻¹ ;wherein said powder is selected from the group consisting of zeolite,silica, carbonate, silicate, sulfate, phosphate, citrate, citric acid ormixtures of these.
 9. A process according to claim 8 in which the powderin step b) is a granular detergent which comprises particles prepared byspray drying, agglomeration, or mixtures of these.
 10. A process formaking a granular laundry detergent component or composition having abulk density of at least 650 g/l comprising the steps of:a) dissolving astructuring agent comprising a polymer in a nonionic surfactant to forma pumpable premix; b) finely dispersing said premix with an effectiveamount of powder characterized in that the fine dispersing of the premixis carried out at an operating temperature of from about 15° to about30° C., and at which said premix has a viscosity of from about 380 toabout 23,000 mPas when measured at said operating temperature and at ashear rate of 25s⁻¹, and that at least some of said powder is in ahydratable form; wherein said powder is selected from the groupconsisting of zeolite, silica, carbonate, silicate, sulfate, phosphate,citrate, citric acid or mixtures of these; and c) spraying water on tothe product of step b).